我目前正在尝试用 Java 编写一个类似点唱机的应用程序，它能够播放任何可能的音频源，但在尝试播放无线电流时遇到了一些困难。
对于播放，我使用JavaZoom的 JLayer，只要目标是直接媒体文件或直接媒体流（我可以播放 PCM、MP3 和 OGG），它就可以正常工作。但是，当尝试播放包含诸如 m3u/pls 文件之类的前媒体数据（我可以通过预先添加检测来修复）或在网页存在时在端口 80 上流式传输的数据的无线电流时，我遇到了困难相同的位置和传输的媒体取决于请求的类型。在后一种情况下，每当我尝试流式传输媒体时，我都会获取 HTML 数据。
隐藏在网页后面的流的示例链接：http
://stream.tn-media.de:8030
这可以在 VLC 中播放，但是如果您将其放入浏览器或我的应用程序中，您将收到一个 HTML文件。
在那儿：
提前致谢！
import java.io.*;
import java.net.*;
import javax.sound.sampled.*;
import javax.sound.midi.*;
/**
* This class plays sounds streaming from a URL: it does not have to preload
* the entire sound into memory before playing it. It is a command-line
* application with no gui. It includes code to convert ULAW and ALAW
* audio formats to PCM so they can be played. Use the -m command-line option
* before MIDI files.
*/
public class PlaySoundStream {
// Create a URL from the command-line argument and pass it to the
// right static method depending on the presence of the -m (MIDI) option.
public static void main(String[ ] args) throws Exception {
if (args[0].equals("-m")) streamMidiSequence(new URL(args[1]));
else streamSampledAudio(new URL(args[0]));
// Exit explicitly.
// This is needed because the audio system starts background threads.
System.exit(0);
}
/** Read sampled audio data from the specified URL and play it */
public static void streamSampledAudio(URL url)
throws IOException, UnsupportedAudioFileException,
LineUnavailableException
{
AudioInputStream ain = null; // We read audio data from here
SourceDataLine line = null; // And write it here.
try {
// Get an audio input stream from the URL
ain=AudioSystem.getAudioInputStream(url);
// Get information about the format of the stream
AudioFormat format = ain.getFormat( );
DataLine.Info info=new DataLine.Info(SourceDataLine.class,format);
// If the format is not supported directly (i.e. if it is not PCM
// encoded), then try to transcode it to PCM.
if (!AudioSystem.isLineSupported(info)) {
// This is the PCM format we want to transcode to.
// The parameters here are audio format details that you
// shouldn't need to understand for casual use.
AudioFormat pcm =
new AudioFormat(format.getSampleRate( ), 16,
format.getChannels( ), true, false);
// Get a wrapper stream around the input stream that does the
// transcoding for us.
ain = AudioSystem.getAudioInputStream(pcm, ain);
// Update the format and info variables for the transcoded data
format = ain.getFormat( );
info = new DataLine.Info(SourceDataLine.class, format);
}
// Open the line through which we'll play the streaming audio.
line = (SourceDataLine) AudioSystem.getLine(info);
line.open(format);
// Allocate a buffer for reading from the input stream and writing
// to the line. Make it large enough to hold 4k audio frames.
// Note that the SourceDataLine also has its own internal buffer.
int framesize = format.getFrameSize( );
byte[ ] buffer = new byte[4 * 1024 * framesize]; // the buffer
int numbytes = 0; // how many bytes
// We haven't started the line yet.
boolean started = false;
for(;;) { // We'll exit the loop when we reach the end of stream
// First, read some bytes from the input stream.
int bytesread=ain.read(buffer,numbytes,buffer.length-numbytes);
// If there were no more bytes to read, we're done.
if (bytesread == -1) break;
numbytes += bytesread;
// Now that we've got some audio data to write to the line,
// start the line, so it will play that data as we write it.
if (!started) {
line.start( );
started = true;
}
// We must write bytes to the line in an integer multiple of
// the framesize. So figure out how many bytes we'll write.
int bytestowrite = (numbytes/framesize)*framesize;
// Now write the bytes. The line will buffer them and play
// them. This call will block until all bytes are written.
line.write(buffer, 0, bytestowrite);
// If we didn't have an integer multiple of the frame size,
// then copy the remaining bytes to the start of the buffer.
int remaining = numbytes - bytestowrite;
if (remaining > 0)
System.arraycopy(buffer,bytestowrite,buffer,0,remaining);
numbytes = remaining;
}
// Now block until all buffered sound finishes playing.
line.drain( );
}
finally { // Always relinquish the resources we use
if (line != null) line.close( );
if (ain != null) ain.close( );
}
}
// A MIDI protocol constant that isn't defined by javax.sound.midi
public static final int END_OF_TRACK = 47;
/* MIDI or RMF data from the specified URL and play it */
public static void streamMidiSequence(URL url)
throws IOException, InvalidMidiDataException, MidiUnavailableException
{
Sequencer sequencer=null; // Converts a Sequence to MIDI events
Synthesizer synthesizer=null; // Plays notes in response to MIDI events
try {
// Create, open, and connect a Sequencer and Synthesizer
// They are closed in the finally block at the end of this method.
sequencer = MidiSystem.getSequencer( );
sequencer.open( );
synthesizer = MidiSystem.getSynthesizer( );
synthesizer.open( );
sequencer.getTransmitter( ).setReceiver(synthesizer.getReceiver( ));
// Specify the InputStream to stream the sequence from
sequencer.setSequence(url.openStream( ));
// This is an arbitrary object used with wait and notify to
// prevent the method from returning before the music finishes
final Object lock = new Object( );
// Register a listener to make the method exit when the stream is
// done. See Object.wait( ) and Object.notify( )
sequencer.addMetaEventListener(new MetaEventListener( ) {
public void meta(MetaMessage e) {
if (e.getType( ) == END_OF_TRACK) {
synchronized(lock) {
lock.notify( );
}
}
}
});
// Start playing the music
sequencer.start( );
// Now block until the listener above notifies us that we're done.
synchronized(lock) {
while(sequencer.isRunning( )) {
try { lock.wait( ); } catch(InterruptedException e) { }
}
}
}
finally {
// Always relinquish the sequencer, so others can use it.
if (sequencer != null) sequencer.close( );
if (synthesizer != null) synthesizer.close( );
}
}
}
我在我的一个处理音频流的项目中使用了这段代码，并且工作得很好。
此外，您可以在此处看到类似的示例： Java Audio Example
Just reading the javadoc of AudioSystem give me an idea.
There is an other signature for getAudioInputStream: you can give it an InputStream instead of a URL.
So, try to manage to get the input stream by yourself and add the needed headers so that you get the stream instead the html content:
URLConnection uc = url.openConnection();
uc.setRequestProperty("<header name here>", "<header value here>");
InputStream in = uc.getInputStream();
ain=AudioSystem.getAudioInputStream(in);
Hope this help.
我知道这个答案来晚了，但我遇到了同样的问题：我想播放 MP3 和 AAC 音频，还希望用户插入 PLS/M3U 链接。这是我所做的：
首先我尝试使用简单的文件名来解析类型：
import de.webradio.enumerations.FileExtension;
import java.net.URL;
public class FileExtensionParser {
/**
*Parses a file extension
* @param filenameUrl the url
* @return the filename. if filename cannot be determined by file extension, Apache Tika parses by live detection
*/
public FileExtension parseFileExtension(URL filenameUrl) {
String filename = filenameUrl.toString();
if (filename.endsWith(".mp3")) {
return FileExtension.MP3;
} else if (filename.endsWith(".m3u") || filename.endsWith(".m3u8")) {
return FileExtension.M3U;
} else if (filename.endsWith(".aac")) {
return FileExtension.AAC;
} else if(filename.endsWith((".pls"))) {
return FileExtension.PLS;
}
URLTypeParser parser = new URLTypeParser();
return parser.parseByContentDetection(filenameUrl);
}
}
如果失败，我会使用 Apache Tika 进行一种实时检测：
public class URLTypeParser {
/** This class uses Apache Tika to parse an URL using her content
*
* @param url the webstream url
* @return the detected file encoding: MP3, AAC or unsupported
*/
public FileExtension parseByContentDetection(URL url) {
try {
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream in = connection.getInputStream();
BodyContentHandler handler = new BodyContentHandler();
AudioParser parser = new AudioParser();
Metadata metadata = new Metadata();
parser.parse(in, handler, metadata);
return parseMediaType(metadata);
} catch (IOException e) {
e.printStackTrace();
} catch (TikaException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
return FileExtension.UNSUPPORTED_TYPE;
}
private FileExtension parseMediaType(Metadata metadata) {
String parsedMediaType = metadata.get("encoding");
if (parsedMediaType.equalsIgnoreCase("aac")) {
return FileExtension.AAC;
} else if (parsedMediaType.equalsIgnoreCase("mpeg1l3")) {
return FileExtension.MP3;
}
return FileExtension.UNSUPPORTED_TYPE;
}
}
这也将解决 HTML 问题，因为该方法将返回FileExtension.UNSUPPORTEDHTML 内容。
我将这些类与工厂模式结合在一起，效果很好。现场检测只需要大约两秒钟。
我认为这不再对您有帮助，但是由于我挣扎了将近三周，因此我想提供一个可行的答案。你可以在 github 上看到整个项目：https ://github.com/Seppl2202/webradio